vigenere1.py

# encoding: utf-8
K="ABCDEFGHIJKLMNOPQRSTUVWXYZ{}"
index=K.index
lk = len(K)

k="????????????"
key_l = len(k)
p="SECCON{???????????????????????????????????}"
c="LMIG}RPEDOEEWKJIQIWKJWMNDTSR}TFVUFWYOCBAJBQ"
p_md5="f528a6ab914c1ecf856a1d93103948fe"

l = len(c)

# 復号化
for i in xrange(l):
    if p[i]=="?": continue
    v = K[(index(c[i]) - index(p[i]) + lk) % lk]
    ks[i%key_l] = v
print ks

vigenere2.py

# encoding: utf-8
K="ABCDEFGHIJKLMNOPQRSTUVWXYZ{}"
index=K.index
lk = len(K)

k="????????????"
key_l = len(k)
p="SECCON{???????????????????????????????????}"
c="LMIG}RPEDOEEWKJIQIWKJWMNDTSR}TFVUFWYOCBAJBQ"
p_md5="f528a6ab914c1ecf856a1d93103948fe"

l = len(c)

ks = list("VIGENERE????")
import itertools, md5
for el in itertools.product(K, repeat=4):
    ks[-4:] = el
    p_tmp = list(p)
    for i in xrange(l):
        p_tmp[i] = K[(index(c[i]) - index(ks[i%key_l]) + lk) % lk]
    digest = md5.new("".join(p_tmp)).hexdigest()
    print digest
    if digest == p_md5:
        print "".join(p_tmp)
        exit(0)